A220621 T(n,k)=Number of ways to reciprocally link elements of an nXk array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.
1, 2, 1, 3, 7, 1, 5, 21, 22, 1, 8, 87, 125, 71, 1, 13, 317, 1189, 765, 228, 1, 21, 1215, 9176, 17084, 4657, 733, 1, 34, 4565, 76955, 282777, 243119, 28373, 2356, 1, 55, 17287, 624227, 5280827, 8608738, 3466455, 172833, 7573, 1, 89, 65261, 5131406, 93905509
Offset: 1
Examples
Some solutions for n=3 k=4 0=self 1=nw 3=ne 4=w 6=e 7=sw 9=se (reciprocal directions total 10) ..6..4..6..4....9..9..6..4....6..4..9..7....6..4..6..4....6..4..6..4 ..0..7..6..4....0..1..1..0....0..0..3..1....0..0..7..0....0..6..4..0 ..3..6..4..0....6..4..0..0....0..6..4..0....0..3..6..4....6..4..6..4
Links
- R. H. Hardin, Table of n, a(n) for n = 1..199
Comments